So, I tried all that, but I'm *still* having issues. This is so bizarre: the problem is the same despite changing inks, and despite cleaning every piece individually. Here's a more thorough history of what happened:
I was running out of ink, so I decided to switch cartridges. I saw this as a decent opportunity to wash the pen out, so I did so (but I didn't take it apart to the extent that is actually necessary). Ever since (and even after performing the second cleaning you suggested), I *can't* get the ink to flow properly.
Understood. I don't have a Metropolitan but do have a Pilot Kakuno, Prera and Plumix/Pluminix so expect its construction is pretty comparable.
Clearly not enough ink is getting through to the nib. Since it doesn't seem to be retained water/moisture it must be something else. I assume it's not dried out ink that is clogging it up as that would have been pretty obvious and your original question would have addressed that instead of a general 'it's not working right and I can't see why'.
I would think then that we have to try various methods of getting more ink through to the feed and nib. Here's what I would try:
i/ invert the pen [with the cap on] and leave it inverted for a few hours/overnight. If everything else is in order then gravity will get the ink to the feed and nib. However, if you don't want to wait try the following options.
ii/ if using a cartridge carefully check the end that connects to the pen and ensure that it is not obstructed. I had this issue the other day and after checking I was surprised that the end was only partially open so it was only allowing a dribble of ink through to the pen. After a quick poke to open it fully the pen worked like a charm.
iii/ With the cartridge securely connected to the pen invert it over something like a cloth or kitchen paper in case of drops and give the cartridge a good squeeze to force ink out of the cartridge to 'prime the feed' with ink. With really stubborn cartridges I have used my teeth to do this but great care to avoid an inky mouth is obviously required!
iv/ If using a converter use the same method as previously described but do the opposite action to that which is used to fill the converter. If it's a converter where you twist the end section then twist it to push the ink up into the pen and thus charge the feed.
v/ If you do all of the above and it's still not flowing nicely then check the nib for obstructions
vi/ If it's still not flowing well then gently tap the end of the nib on some scrap paper to encourage the ink flow. This is a 'ain't nobody got time for that' version of the gravity method
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vii/ hold the nib in some wet tissue paper. This should encourage the ink to flow through to the tissue.
viii/ wetting the top of the nib can also help here. You might want to use some tap water but I just shove a finger in my mouth to moisten it.
One or more of the above should resolve ink flow generally for me. If not then ensuring the feed and the nib are aligned correctly might be required. In good lighting, have a close look at the hole on the top of the nib. You should see that below that there is a line on the feed. This needs to be aligned in the centre of the hole so that the ink will flow along the feed to the tipping point i.e. the end of the nib that touches the paper.
Hopefully this should more than cover it but if not then you might have to delve into checking that the tines are not misaligned. Hopefully however that is fun for another day
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